Microelement deficiency corrector for farmland and process for preparation thereof

ABSTRACT

The corrector comprises a mixture of trace elements, in hydrated sulfate form, optionally containing carbonates and including iron, magnesium, manganese and zinc, with the following typical analysis: Magnesium 3.5-6%; iron 12-19%; Manganese 1-1.5%; zinc 0.2-0.3% and organic matter 0-45%. 
     The process comprises mixing 50-66% of the by-product of manufacture of titanium bioxide via sulfate, 5-10% alkaline earth carbonate or magnesite and, optionally, 10-45% organic matter, grinding the mixture, granulating it and drying it, cooling it and screening it. 
     The corrector is used in agriculture to prevent and control ferric chlorosis, to favor physiological processes of harvests in which iron takes part and to avoid deficiencies of manganese and zinc in farmland.

This application is a continuation of U.S. patent Ser. No. 08/343,082,filed Nov. 21, 1994, and now abandoned which is a continuation of U.S.patent application Ser. No. 07/898,788, filed Jun. 12, 1992, and nowabandoned.

TECHNICAL FIELD OF THE INVENTION

The present invention fits in the technical field of utilization ofby-products of manufacture of titanium bioxide via sulfate, and,specifically it refers to a microelement deficiency corrector forfarmland and process for preparation thereof.

PRIOR ART OF THE INVENTION

As is known, the manufacturing process of titanium bioxide via sulfateinvolves a first step of attack of ilmenite with sulfuric acid, followedby a hydrolysis step that leads to said titanium bioxide which is apigment with important industrial uses. The effluent coming from thehydrolysis step is subjected to a process of crystallization from whichthe so-called "copperas" or heptahydrated iron sulfate results withagricultural uses and that is used to manufacture mixed feeds and that,in ferric sulfate form, is used to treat water.

The crystallization eater is concentrated and afterwards filtered,recycling the filtrate in the first attack step with sulfuric acid.

The residue of filtration is a metal sulfate mixture that cannot bestored as waste material due to leaching problems, whose only usedeveloped up to now has been the production of sulfuric acid by means ofroasting, which involves costly investments.

Afterwards some patents which describe the use of this by-product in themanufacture of sulfuric acid are indicated:

Bayer's European patent "A" which refers to the use of a Fundabac filterfor the separation of salts.

Bayer's European patent "B" which refers to a process to elaboratesulfuric acids which contain metal sulfate, called "fine acids," bymeans of concentration by evaporation.

Bayer's European patent 139120 "B" which refers to the production ofsulfur dioxide by thermal decomposition of metal sulfates andsimultaneous roasting of sulfide ores.

Bayer's European patent 145984 "A" which refers to a sulfate process inwhich the residual acid and the metal sulfates are recycled, at least inpart, at the digestion step.

Bayer's European patent 0194544 "A" which refers to a process forrecirculation of sulfuric acid used containing metal sulfates, by meansof evaporation until a concentration of 40-85% of H₂ SO₄.

The basic advantage that the present invention provides over the presentprior art is that it makes it possible to transform the cited by-productinto a marketable product by means of a simple process in a low costinstallation.

DESCRIPTION OF THE INVENTION

The present invention refers to a microelement deficiency corrector forfarmland and to a process for preparation thereof.

A by-product which is a mixture of metal sulfates having the followingtypical analysis is obtained in the manufacturing process of titaniumbioxide. Throughout this specification, it will be understood that"typical elemental analysis" refers to the weight percentage of eachitem, primarily elemental, (without regard to the total weight of thecompound of which it forms a part) relative to the total weight of themixture.

    ______________________________________                                               (*) S 19%                                                                     Fe    21.3%                                                                   SiO.sub.2                                                                           0.06%                                                                   Al.sub.2 O.sub.3                                                                    0.45%                                                                   CaO   0.01%                                                                   Zn    0.34%                                                                   Pb    0.03%                                                                   As    0.01%                                                                   MgO   0.25%                                                                   Mn    1.65%                                                                   Cu    0.01%                                                                   Sn    12 ppm                                                                  Bi    1 ppm                                                                   Co    40 ppm                                                                  Cd    1 ppm                                                                   Hg    0.01 ppm                                                                Ni    30 ppm                                                                  H.sub.2 O                                                                           8.2%                                                                    H.sub.2 SO.sub.4                                                                    15.1%                                                                   TiO.sub.2                                                                           1.5%                                                             ______________________________________                                         (*) Corresponding to sulfuric acid and sulfates                          

This by-product is used as raw material in the process of the presentinvention in a proportion of 50-56%, along with 5-10% of alkaline earthcarbonates or magnesites and, optionally, 10-45% of organic matter:manure or lignites.

The deficiency corrector obtained is a mixture of trace elements, inhydrated sulfate form, that can contain carbonates. The metals thatessentially form part of the composition thereof are iron, magnesium,manganese and zinc.

The typical analysis of this deficiency corrector is the following:

    ______________________________________                                        Magnesium (as MgO)                                                                             3.5-6%                                                       Iron (as Fe(II)  12-19%                                                       Manganese        1-1.5%                                                       Zinc             0.2-0.3%                                                     Organic matter   0-45%                                                        ______________________________________                                    

The process of the invention is characterised because it comprises thefollowing steps:

a) introducing in a mixer 50-60% of by-product from manufacturingtitanium bioxide via sulfate, 5-10% of alkaline earth carbonate ormagnesite and, optionally, 10-45% of organic matter selected from manureand lignites and mixing for 5-10 minutes;

b) passing the mixture coming from step (a) through a grinder, where thesize thereof is reduced to particles between 0 and 2 mm;

c) dosing the product coming from step (b) in a granulating machinewhere it is transformed into powder in sphere of different sizes;

d) passing the powder of the granulating machine to a rotary dryer withan air intake temperature between 100° and 500° C.;

e) passing the granulate coming from the dryer to a cooler from which itcomes out at a temperature between 40° C. and room temperature;

f) passing the product, once cool, through a screen which selects thegranulate by sizes between 1 and 5 mm. of diameter and, subsequently,packaging it.

Hereinafter the typical analysis of two of the correctors obtained bythe process which has just be described are provided:

1) Typical analysis:

    ______________________________________                                        Magnesium (as MgO)                                                                             5.8%                                                         Iron (as Fe(II)) 19.0%                                                        Manganese        1.5%                                                         Zinc             0.3%                                                         ______________________________________                                    

2) Typical analysis:

    ______________________________________                                        Magnesium (as Mg O)                                                                             3.5-4%                                                      Iron as Fe (II))  12.13%                                                      Manganese         1-1.5%                                                      Zinc              0.2%                                                        Organic matter (manure)                                                                         10%                                                         ______________________________________                                    

The correctors of the present invention are used in agriculture toprevent and control the problem of ferric chlorysis, the magnesiumcontents favor the physiological processes in which the iron intervenes.The manganese and zinc contents suffice to avoid deficiencies thereof.

These correctors can be used within a wide range of deifications, in theneighborhood of 10-2000 g/plant. The following can be mentioned asrepresentative:

Young trees and vines: 100-600 g/plant

Trees of complete production: 600-2000 g/plant

Greenhouse and stock plants: 10-60 g/plant

EMBODIMENTS OF THE INVENTION

The present invention is additionally illustrated by means of thefollowing examples, which are not restrictive of the scope thereof,which is exclusively defined by the attached set of claims.

EXAMPLE 1

50% of the by-product from the manufacture of titanium bioxide viasulfate, 5% magnesium oxide and 45% sheep manure are introduced in amixer and mixed for 8 minutes. The mixture is removed and passed to thegrinder. The fine product is continuously poured into a granulatingmachine from which the formed granulates pour over. These granules arepassed to the dryer in which a stream of air at 400° C. in introduced.

From the opposite end, the dry granulated product flows at 50° C. Fromhere the product passes to the cooler feed by a stream of air at 10° C.,in back stream. At the end of the cooler the product reaches atemperature of 25° C.

The granulate is raised to a double screen with mesh of 5 and 1 mm.openings, respectively, collecting the fraction that remains betweenboth screens. The granule selected is packaged by weighing in 50 kg.raffia bags.

EXAMPLE 2

Two of the typical analyses corresponding to two correctors obtained bythe process of the invention are given hereinafter:

    ______________________________________                                        Corrector 1                                                                   Typical analysis:                                                             Magnesium (as MgO)                                                                              5.8%                                                        Iron (as Fe (II)) 19.0%                                                       Manganese         1.5%                                                        Zinc              0.3%                                                        Corrector 2                                                                   Typical analysis:                                                             Magnesium (as MgO)                                                                              3.5-4%                                                      Iron (as Fe (II)) 12.13%                                                      Manganese         1-1.5%                                                      Zinc              0.2%                                                        Organic matter (manure)                                                                         10%                                                         ______________________________________                                    

We claim:
 1. A microelement deficiency corrector for farmland derivedfrom the by-product of the manufacture of titanium bioxide via sulfate,said corrector comprising a mixture of trace elements, in hydratedsulfate form, and containing alkaline earth carbonates or magnesite,whose essential metals are iron, magnesium, manganese and zinc and whosetypical elemental analysis based on the total weight of said mixture isthe following: magnesium (as MgO), 3.5-6%; iron (as Fe II), 12-19%;manganese, 1-1.5%; zinc, 0.2-0.3%; and having 10-45% organic matter,50-95% of said by-product and 5-10% of said alkaline earth carbonates ormagnesite.
 2. The microelement deficiency corrector according to claim 1having the following typical elemental analysis based on the totalweight of said mixture: magnesium (as MgO), 5.8%; iron (as Fe II), 19%;manganese, 1.5%; and zinc, 0.3%.
 3. The microelement deficiencycorrector according to claim 1 having the following typical elementalanalysis based on the total weight of said mixture: magnesium (as MgO),3.5-4%; iron (as Fe II), 12-13%; manganese, 1-1.5%; zinc, 0.2%; andorganic matter, 10%.
 4. The microelement deficiency corrector accordingto claim 1 comprising 50% of said by-product, 5% magnesium oxide, and45% organic matter, wherein said by-product, magnesium oxide, andorganic matter are mixed for 5-10 minutes, passed through a grinder toform particles between 0-2 mm in diameter, granulated, dried, and cooledto form said corrector.
 5. The microelement deficiency correctoraccording to claim 4 wherein said organic matter comprises manure. 6.The microelement deficiency corrector according to claim 1 wherein saidorganic matter comprises manure.